Portable electronic instruments such as oscilloscopes are often required to be portable for testing devices at various locations. Accordingly, they are typically provided with carrying handles. The handle is typically a bail handle pivotally mounted to opposite side panels at positions near the front panel. The handle has arms that extend parallel to the side panels, with a cross member connecting the handle ends.
A lightweight handle provides improved portability, and a slim handle provides a compact profile and an aesthetic appearance. Having a broad cross section provides a large surface for comfortable carrying. However, these desired qualities are typically contrary to the desire that the handle be stiff. Stiffness provides a quality feel by preventing sagging under load, and allows the handle to be used as a support leg. Moreover, a stiff handle resists unwanted torsional flexing in which the arms are pivoted to different angles twists, which can potentially lead to the arms locking in a different angular positions. Essentially, a closed or tubular cross section provides good stiffness, although it is not readily moldable by conventional techniques.
Tubular members with circular cross sections have been effective to provide relatively lightweight and stiff handles and to resist collapse under limited lateral compressive loads, such as occur during secondary molding operations when a conformal elastomeric grip is molded about a rigid plastic handle. Handles with non-circular cross sections are susceptible to collapse under these substantial loads. While a thin wall design may be acceptable for the limited forces faced during normal use, it may fail during secondary molding. Thus, even designers using advanced plastic molding techniques to create hollow handles of wide diverse shapes are limited in the cross sectional aspect ratio they may employ. There remains a need for a readily moldable instrument handle with good torsional strength, and particularly for a handle with a non-circular cross section.
The embodiments disclosed herein overcome these limitations by providing an elongated bail handle for an electronic instrument housing with opposed ends providing handle mounts. The handle has an elongated intermediate portion extending the width of the instrument, and a pair terminal arm portions each connected to the intermediate portion and having a free end for connection to a respective end surface of the housing. The intermediate portion defines an elongated bore, and a reinforcing bar laterally spans the bore to connect opposed walls of the intermediate portion. The arm and bore may have an oblong cross section, with the bar spanning the short span. The bar may define a passage, and an overmolded handle grip encompassing the reinforcing bar may have material filling the passage to secure it to the handle.